1. Technical Field
The present disclosure relates to surgical systems and instruments, and methods of using the same to prevent the occurrence of restenosis and, more particularly, to surgical systems including energized/energizable stents, and methods of using the same in the prevention of restenosis.
2. Background of Related Art
Various techniques have been developed to treat many different conduits in the body when these conduits become reduced in size due to the existence of a stenosis or have been completely occluded for various reasons. With respect to the vascular pathways, angioplasty is used to open an artery or blood vessel in the region where stenosis or occlusion has occurred. A typical angioplasty procedure consists of making a small incision through the body and into a blood vessel and then maneuvering a guide wire through the vascular system to a point beyond the stenosis or occlusion. A hollow catheter with a deflatable balloon near the distal end of the guide wire is threaded over the guide wire and advanced to the point of stenosis or occlusion. The balloon is then inflated and deflated several times to widen the constricted area, and is then withdrawn from the body.
Unfortunately, although the angioplasty procedure does markedly reduce the area of stenosis or occlusion, many patients exhibit a reoccurrence of the stenosis (i.e., restenosis) within a few months of the original procedure.
Although the original stenosis occurs by means of the build up of plaque over a relatively long period of time, experimentation has lead many to believe that the reoccurrence of the stenosis after the original angioplasty procedure is unrelated to the cause of the original stenosis. It is believed that the inflation of the balloon catheter used in the angioplasty procedure causes irritation to the blood vessel. This irritation produces a mechanism of action called hyperplasia, inducing the inner layer of the blood vessel cells to rapidly reproduce, thereby causing the restenosis.
Conventionally, expandable devices, called stents, are used to maintain the inner diameter of a body lumen such as an artery. Although stents are most commonly used after angioplasty, to maintain vascular patency and help in the prevention of restenosis, stents may also be used for repair of aneurysms, stabilization of interior vessel tubes such as bronchial tubes, retention of emboli and plaque, and prevention of vessel collapse. The stents are placed at a desired location within a body lumen through a guide catheter or similar device and are expanded, by various known methods, within the lumen until they are opposed to the walls of the lumen at a preferred diameter.
Drug eluting coatings are commonly employed to reduce the irritation and/or inflammation and further reduce the possibility of restenosis. While drug eluting stents are marginally effective, such drug eluting stents have a finite period of time of drug delivery based on the rate at which the drug eluting coating is dissolved.